Cystic fibrosis (CF) is the most common severe autosomal recessive disorder in the Caucasian population. Beside the major mutation delta F508, which accounts for approximately 68% of all CF chromosomes, more than 350 different point mutations leading to this disease have been detected and communicated to the 'Cystic Fibrosis Genetic Analysis Consortium'. As these mutation are scattered about the whole CFTR gene we used denaturing gradient gel electrophoresis as a rapid method for screening a large number of CF patients for point mutations in the CFTR exons.